Novel barium zirconate titanate-based lead-free ceramics with stably high energy storage performance over a broad temperature and frequency range

Lead-free relaxor ferroelectric ceramics with high recoverable energy storage density and energy storage efficiency over a broad temperature and frequency range are attractive for pulsed power capacitor applications. In this work, novel barium zirconate titanate-based lead-free relaxor ferroelectric ceramics are designed via introduction of Bi(Zn 0.5 Sn 0.5 )O 3 with heterovalent ion substitution at both A- and B-sites which could disrupt long-range order, induce polar nanoregions (PNRs), and reduce remnant polarization ( P r ). The (1 −  x )Ba(Zr 0.15 Ti 0.85 )O 3 – x Bi(Zn 0.5 Sn 0.5 )O 3 ((1 −  x )BZT– x BZS) ( x  = 0.02, 0.06, 0.10, and 0.14) ceramics were prepared using a conventional solid-state reaction method. In addition, the structure, dielectric, ferroelectric, and energy storage properties of (1 −  x )BZT– x BZS ceramics were systematically studied. All (1 −  x )BZT– x BZS ceramics exhibited pure perovskite structure. With the increase of BZS content, the relaxor ferroelectric feature of (1 −  x )BZT– x BZS ceramics tended to increase gradually, and slim linear P – E loops were obtained in x  = 0.10–0.14. A high recoverable energy storage density W rec of 2.16 J/cm 3 and a high energy storage efficiency η of 90.3% were simultaneously achieved in x  = 0.10 at 250 kV/cm, together with excellent temperature and frequency stability, which were superior to those of the reported barium zirconate titanate-based ceramics. Our work provides an effective strategy to optimize the energy storage performance of lead-free barium zirconate titanate-based ceramics toward practical applications.